15 Nov 1941M-171 fires two torpedoes against ' what is identified as ' a merchant of 8000 tons of Kirkenes. Both torpedoes missed their target.

5 Dec 1941M-171 fires two torpedoes against ' what is identified as ' a merchant of 4000 tons north of Vardo, Norway in position 70°30'N, 30°58'E. Both torpedoes missed their target.

27 Jan 1942M-171 fires two torpedoes against ' what is identified as ' a merchant of 4000 tons of the Syltefjord in position 70°60'N, 30°58'E. Both torpedoes missed their target.

20 Mar 1942M-171 fires a torpedo against ' what is identified as ' a auxiliary minesweeper off the Varangerfjord in position 70°00'N, 30°67'E. The torpedo missed its target.

22 Mar 1942M-171 fires a torpedo against ' what is identified as ' a submarine off the Varangerfjord in position 70°08'N, 30°67'E. The torpedo missed its target. The attack was most likely against U-456 that arrived at Kirkenes that day.

29 Mar 1942M-171 fires two torpedoes against ' what is identified as ' a submarine in position 70°20'N, 31°25'E. Both torpedoes missed their target. The attack was most likely against U-585 that had departed Kirkenes the previous day.

29 Apr 1942M-171 torpedoed and sank the German merchant Curityba (4969 GRT) off the Varangerfjord in position 70°12'N, 30°57'E.

Curityba had the auxiliary minesweepers M 5403 and M 5407 aboard, these were also lost when the ship sank.

23 May 1942While on patrol of the Varangerfjord, M-171 fires two torpedoes against ' what is identified as ' a merchant of 11000 tons. The target was in fact the much smaller Norwegian merchant Vard? (860 GRT, offsite link). The target was not hit.

19 Jun 1942M-171 fires two torpedoes against ' what is identified as ' a merchant of 4000 tons of the Varangerfjord, north of Kirkenes. Both torpedoes missed their target.

13 Dec 1942M-171 fires two torpedoes against ' what is identified as ' a merchant of the Varangerfjord. Both torpedoes missed their target.

5 Jan 1943M-171 fires two torpedoes against ' what is identified as ' a merchant of 12000 tons off the Syltefjord in position 70°67'N, 30°80'E. Both torpedoes missed their target.

29 Jan 1943M-171 torpedoed and damaged the German transport Ilona Siemers (3243 GRT) off the Persfjord in position 70°52'N, 30°92'E.

18 Feb 1943M-171 fires two torpedoes against ' what is identified as ' a auxiliary patrol vessel of the Syltefjord. Both torpedoes missed their target.

27 Feb 1943M-171 fires two torpedoes against the German auxiliary patrol vessel Guschi II of the Varangerfjord. Both torpedoes missed their target.

5 Apr 1943M-171 fires two torpedoes against ' what is identified as ' a merchant of 2500 tons off the Varangerfjord. Both torpedoes missed their target

12 Oct 1944M-171 fires two torpedoes against ' what is identified as ' a auxiliary patrol vessel of the Syltefjord in position 70°39'N, 30°30'E. Both torpedoes missed their target.

16 Oct 1944M-171 fires four (???) torpedoes against ' what is identified as ' a merchant of 8000 tons in the Persfjord / Syltefjord area. All torpedoes fires missed their target.